Help - transmission slipping

[smwmustang]

So I have 177,000 miles on the X but the transmission, driveshaft and torque convertor are all only 2 1/2 years old with about 60,000 miles on them.

I gave it some gas the other day in normal driving mode to go around a vehicle and the rpm's jumped to redline and then dropped into gear. I was only about a mile from home but at the next stop sign it jerked into gear so hard I truely thought I had whip lash. I have parked it and not driven it again until I find out what is wrong.

Any help or comments are greatly appreciated as to try and narrow down what is wrong. Is there a place to check the transmission fluid. Sorry this is my first BMW and I am still learning the truck.

Thanks,

Shawn